1. THE TINTS OF OLD GLASS
Old glass is darkly brilliant. It is not whitely crystal as modern glass is; the eye can only see what it looks for, ever, and to uninstructed eyes all glass is merely glass-colour, but the experienced collector sees that there are many different tints and tinges in the crystal of glass. These tints and tinges are the chief guide, test, and principle by which one judges whether a piece of glass is one of the nineteenth century, eighteenth century, or seventeenth century, as the case may be.
To judge the tint, place the piece of glass upon a white tablecloth, near to a tumbler or decanter known to be modern because of recent purchase from an ordinary vendor of household glass. The eye, looking for it, will then notice in the two pieces of glass a striking difference of tint, if one of them is old, that is; the old piece is not only darker than the white of the tablecloth, but darker than the piece of modern glass. And the darker (or sootier) its tint the older the glass, as a rule. Tint or tinge is a constant feature in old glass, and an obvious feature directly the eye knows what to look for. Varieties of dark tint may be detected, and by these varieties the bit of glass may be dated, its period determined, and its age assigned.
HUNTING GOBLET, DOME FOOT
If you place near each other, upon a white damask cloth, a glass of Charles II date, a William and Mary glass, a George III glass, and a Victorian glass, you will notice a darkening and then a whitening in tint (though not a brightening) as your eye travels from the oldest glass to the most modern. By “tint” or “tinge” I do not mean “colour,” in the sense of red or green or blue; I will deal with coloured glass later on. By “tint” or “tinge” I mean the shade of leaden, darkish hue in the metal from which the glass article was blown or moulded. This tint or tinge was inherent in the molten glass, before shaping and cooling began. The metal or raw material was mixed according to recipe—each glassworks had its own recipe—and one of the materials was lead. The older the Georgian glass, the more impure the metal—that is, the fuller of lead oxides—and therefore the darker; what are called improvements in glass-mixing have gradually eliminated the oxides, and therefore the leaden tint or tinge also; it is astonishing how many different shades and tinges of darkness (in that sense) a cabinet of old glass can show. In a few glasses the bowl is pale sapphire or aquamarine colour, the stem being the tint of plain glass.
“TRAFALGAR” GLASS: RUMMER ON BALUSTER STEM AND RAISED FOOT; EXAMPLE OF ELABORATE ENGRAVING
The glass collector exercises his sight and applies the test; it enables him to detect a counterfeit, though in shape and general appearance it imitates the genuine antique; it is too whitely crystal, too tintless to be old. Curio-shop windows at Brighton, for instance, are full of frauds in glass, chiefly cut-glass, or glass moulded to resemble cut-glass; but the chalky-white tint betrays and condemns them, and the instructed collector will not be taken in. Also he will recognize genuine Waterford glass by its own tinge of colour, and genuine Cork glass in a similar way; he will see that old Dutch-made glass, when thick, has a smeary, milk-and-watery tint, and when thin has a flashy, meretricious absence of deep tinting: he will learn that old Stourbridge glass was whiter than antique Bristol or Newcastle glass, and sometimes was milky-white; in course of time and practice he will come to be able to “date” and “place” a piece of old glass at sight, as well as instantly to reject a fraud.
The tints of Irish-made glass. Glass made at Waterford, late in the eighteenth century and early in the nineteenth, was a fine product, often exquisitely cut: it is distinguishable in more than one way, but has a characteristic tinge which, once seen, is unmistakable. I cannot find exact words for it, it is not a blue nor a green nor a blackish tint, but is something of all three, and was due to excessive presence of oxide of lead. Nobody has done any research as to Irish-made glass, and people suppose that Cork-made glass resembled the Waterford glass, but that is very unlikely, because each factory mixed according to its own recipe, and also used a different variety of each of the raw materials common to all glass. In point of fact, Cork glass is “duller” than Waterford, and it has quite a different, a pale, almost dun or yellowish, tinge, particularly visible in the thicker parts; a good many lustre-ornaments seem to have been made at Cork. Belfast glass was yellowish, too, if we may judge by the tint of Williamite glasses.